I would like to try and simplify calculation of the breakeven point for people who might have ordered a mining rig from butterfly Labs (BFL).
I don't think that the increase in hash rate from other ASIC miners is particularly relevant to calculations of breakeven. This is because of the much bigger hash figure created collectively from every Tom Dick and Harry switching on their computer at night to make Bitcoins. Now that Bitcoin as has become so well-known there must be millions of teenagers whose parents pay for electricity that will quite happily run their computers with a couple of graphics cards in their bedroom 24/7 who collectively become the new competition. There will even be some IT managers sneakily running their vast departments the same way at night.
I don't think it's unreasonable to assume that with all the publicity generated about Bitcoin in the media that in the next few months there will be several million additional home or business computers switched on overnight worldwide to mine Bitcoins just using the CPU and Graphics cards. The total computation output of 1 million home or business computers at say 50 MHs is equivalent the output of 10,000 Jalapeno rigs, or equivalent to 1,000 rigs at 50 GHs. Even if they don't make money a valuable lesson may be be learned by home computer owners is that leaving their equipment on, whether mining or idle is costing somebody money!
In the breakeven calculation, the more important figure is the
difficulty level. This level is now 7,672,999 and increases every two weeks by about 18%. The latest change from 7,672,999 to 9,121,259 is 18.88745%.
This analysis shows you a method to calculate profits by adjusting the difficulty for each month. You can decide your own rate of increase in difficulty and adjust the present publicly published figure of 18% up or down.
I have compiled the following table showing the difficulty level extrapolated from present figures:
Date Difficulty Level
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17/04/2013 9,121,259.40
01/05/2013 10,842,874.22
14/05/2013 12,889,439.52
27/05/2013 15,322,288.88
09/06/2013 18,214,332.46
22/06/2013 21,652,242.00
05/07/2013 25,739,048.34
18/07/2013 30,597,229.13
31/07/2013 36,372,379.34
13/08/2013 43,237,574.67
26/08/2013 51,398,558.38
08/09/2013 61,099,907.29
21/09/2013 72,632,361.46
04/10/2013 86,341,537.41
17/10/2013 102,638,285.93
30/10/2013 122,011,004.83
12/11/2013 145,040,275.80
25/11/2013 172,416,263.88
08/12/2013 204,959,401.01
21/12/2013 243,644,973.60
03/01/2014 289,632,350.94
16/01/2014 344,299,730.35
29/01/2014 409,285,440.44
11/02/2014 486,537,040.22
24/02/2014 578,369,685.59
09/03/2014 687,535,512.33
22/03/2014 817,306,114.92
22/03/2014 971,570,593.08
22/03/2014 1,154,952,104.36
22/03/2014 1,372,946,415.71
22/03/2014 1,632,086,606.27
22/03/2014 1,940,138,857.49
22/03/2014 2,306,335,198.06
22/03/2014 2,741,650,178.95
If we now assume that butterfly labs will deliver in July. Let's say 31st of July (so they won't be lying), then the average hash rate per month can be calculated for a Jalepino 5GHs rig as an example.
Month 1 is August 2013.
Month Average difficulty Earnings
------------------------------------------
1 39,804,977.00 $186
2 56,249,232.83 $131
3 79,486,949.44 $92
4 112,324,645.38 $65
5 158,728,269.84 $45
6 224,302,187.31 $31
7 316,966,040.65 $22
8 447,911,240.33 $15
9 632,952,598.96 $10
10 894,438,354.00 $6
11 1,263,949,260.04 $4
12 1,786,112,731.88 $2
13 2,523,992,688.50 $1
As you can see the earnings diminish rapidly due to the difficulty level increasing, and are based on a bitcoin price of $100.
The above earnings figures are taken from the profit calculator on the butterfly labs website, but importantly I have used a separate calculation for each of the twelve months, using increasing levels of difficulty for each month which their calculator surprisingly omits. I contacted a representative from butterfly labs about this glaring omission from their calculation page on the website and their response was that the increasing difficulty was a perfectly realistic assumption, but that it should be entered into the calculator by buyers for themselves, and it was not the responsibility of the company to do this. In my view their calculator is misleading and misrepresents profit potential as the average consumer would use the existing difficulty level and believe the unlimited riches promised by the company.
Profitability will clearly depend on when you receive delivery. The following are three scenarios:
1. End-July Delivery.
The total earnings are $609. The basic cost of the unit is $274, or $312 if you are shipping to the United Kingdom by standard air mail. So the profit for the year is $297 if you received at end July and start mining from 1st August.
2. End-August delivery.
Now let's say you are unlucky to receive your unit at end of August. Your estimated earnings for the first year would then be $423 less $312 = $111.
3. End-September delivery.
If you received your unit at the end of September earnings would be $292 less $312, and you would make an annual loss of $20 !!!
So the crux for miners buying from butterfly labs is when they will actually receive the unit.
The website states: "Pre-order Terms: Bitforce SC (ASIC) products are in final stage development with initial shipping scheduled for the last half of April 2013. Products are shipped according to placement in the order queue, and delivery may take 2 months or more after order. All sales are final." Their voicemail service by contrast recently stated shipping will commence July 2013, but now has simply states "soon".
If you placed your unit early and receive end-July, you might be lucky to double your money. If however you ordered later, or the company delays orders further, and you receive end-September or later your earnings may be squat!
I hope this helps people who are thinking of buying the unit from Butterfly labs.
It seems the trick to staying ahead is by keeping up-to-date with the latest technology, already having existing fast hardware, and knowing the right timing to incrementally upgrade, in order to keep pace with the difficulty level.